Trailers having goose neck tongues are equipped with hitch assemblies to connect the trailer to a towing vehicle such as a pickup truck. The hitch assemblies are also connectable to the draw bars of tractors. Upright support structures of the hitch assemblies are adjustable in length to accommodate different elevations of coupling structures of the towing vehicles. The vertical adjustment of the hitch assemblies has been achieved in various ways. Telescopic members that are pinned together are shown in U.S. Pat. No. 3,527,476 U.S. Pat. No. 3,796,444. A hydraulic cylinder is used to change the elevation of the hitch assembly in U.S. Pat. No. 2,844,265. Additional attaching structure is used to provide the hitch assembly with a low hitch point in U.S. Pat. No. 3,733,089. Screw threads are used in hitches shown in U.S. Pat. No. 3,035,856 and U.S. Pat. No. 3,843,163.